To what extent did the arrival of Europeans influence the scope and conduct of the spice trade?

The arrival of the Europeans did not have a tremendous impact on the scope and conduct of the spice trade. Instead, its main effect was simply to change the participants in the trade. Before the Europeans came, the trade was conducted with Muslim traders. After the Europeans came, it was conducted with various European nations.

For example, when the Portuguese took the spice trade from the Muslims, they were not strong enough to colonize in any real way. All they were able to do was to hold trading posts on the Indian and Chinese coasts. When the Dutch came about a century later, they were able to take more control and to set up actual plantations of their own, but this was much later than would be indicated by your question.